Disposable diaper

ABSTRACT

A disposable diaper wherein interrupted transverse and angled convergent lines of compression are applied to a diaper blank with adhesive adjacent the convergent lines to provide a diaper having a relatively rounded, unstressed crotch-forming portion and a rounded leg outfold when applied; yet which is relatively thin in its folded condition prior to application.

United States Patent- Nystrand Jan. 14, 1975 DISPOSABLE DIAPER 3,461,871 8/1969 Foote 128/284 7 3,710,797 1/1973 M 128/284 [75] Invent: 'P Dame Nysmmd, Green 3,744,494 7/1973 128/287 3,774,610 11/1973 Eckert et al. 128/287 [73] Assignee: Paper Converting Machine Co.,

Green y Primary ExaminerRichard A. Gaudet [22] Filed: Oct 5, 9 3 Assistant Examiner-R. Opitz Attorney, Agent, or Firm-Dawson, Tilton, Fallon & No.1 Lungmus Related US. Application Data [63] Continuation-impart of Ser. No. 297,750, Oct. 16,

1972, abandoned, and Continuation-impart of Ser. [57] ABSTRACT Flo-37312471111116 1ab51n 9m A disposable diaper wherein interrupted transverse and angled convergent lines of compression are applied to a diaper blank with adhesive adjacent the congll. vergent lines to provide a diaper having a relatively [58] Fie'ld [28 4 287 rounded, unstressed crotch-forming portion and a rounded leg outfold when applied; yet which is rela- [56] References Cited tively thin in its folded condition prior to application.

1 Claim, 4 Drawing Figures DISPQSABLE DIAPER This application is a continuation-in-part of my copending applications Ser. No. 297,750, filed Oct. 16, 1972, and Ser. No. 373,247, filed June 25, 1973, now both abandoned.

BACKGROUND AND SUMMARY OF INVENTION Increasingly those in the art of producing disposable diapers have striven to provide suitably prefolded diapers so that the diaper conforms readily and fits comfortably on the infant. Exemplary of this are the diapers seen in US. Pat. Nos. 3,196,874 and 3,710,797. The diaper of the instant invention is an improvement on the diapers in the above-mentioned patents.

The inventive diaper provide interrupted transverse and foreshortened angled convergent lines of compression so as to develop a single legfold diaper and with legfold adhesive adjacent the interrupted angled convergent lines of compression to develop an unusually advantageous leg outfold. The invention lends itself to a high-speed, simple, folding technique. Further, when the diaper is opened and laid on a table, preparatory to positioning the baby on the diaper, the stress lines between the adhesive spots on the inner diaper face cause the outer central portions to naturally drape downwardly for a snug, comfortable fit around the babys legs, while the stress lines at the same time create a pouch in the center of the diaper which has excellent containment characteristics. Because of the combination of lines of compression, i.e., lines of incipient folding, a stack of single legfold diapers has a height twothirds to three-quarters of a stack of double legfold diapers, which represents a considerable saving in carton, case, warehousing and shipping costs.

DETAILED DESCRIPTION The invention is described in conjunction with an illlustrative embodiment in the accompanying drawings, in which:

FIG. 1 is a plan view of a diaper blank prior to foldmg;

FIG. 2 is a plan view of the folded diapers; FIG. 3 is a side elevational view of the diaper of FIG.

FIG. 4 is a plan view of the unfolded diaper showing the various stress lines.

In the illustration given, and with reference first to FIG. 1, the numeral designates a diaper blank." By this, I refer to the precursor of the final disposable diaper, but one wherein the essential, conventional elements are already assembled. For example, the blank 10 includes an outer impermeable sheet, a layer of liquid absorbing material, and an inner liquid permeable sheet, all united perim etrically. Such blanks are provided in a connected stream (prior to scoring and adhesive application), and are designated 1 l in the left hand portion of FIG. 5. Conventional apparatus is available for the production of such a multiply diaper web.

The diaper blank in FIG. 1 is seen to include a plurality of lines of compression, i.e., lines of incipient fold: ing. First, reference is made to an interrupted, centrally positioned, transverse line 12 which includes line segments 12a and 12b. The middle portion of the line 12, Le, the interrupted portion designated 120 in FIG. 1, provides a crotch-forming portion of the diaper (see FIG. 4) which is relatively rounded and unstressed, and which has excellent containment characteristics. The

development of fold lines as by compression, creasing, etc. may impair the containment characteristic and, in extreme cases, result in leakage. In some instances the transverse line 12 may be continuous, but creased only lightly, particularly in the central portion.

Associated with each line segment 12a or 12b, as the case may be, are a pair of inwardly convergent foreshortened lines of compression and which are disposed at about 45 relative to the associated line segment. As can be readily appreciated from FIG. 1, the angled lines associated with the line segment 12a are designated 13 and 14, while those associated with the line segment 12b are designated 15 and 16. It will be seen that if the lines 13 and 14 were extended, they would converge on the line 12, the same being true in the case of the lines 15 and 16. The foreshortening aids in developing the advantageous unstressed crotch-forming portion.

Adhesive is applied in the spots designated 22, 23, 24, and 25 in FIG. 1, with each spot 22-25 being adjacent a longitudinal edge, but spaced inwardly therefrom, and also adjacent to but spaced from an associated convergent line of compression l3l6, respectively. Before leaving FIG. 1, reference is made to the tabs 26 and 27 which are provided in conventional fashion to secure the diaper in place about the infant's waist, and which are conventionally provided on the diaper web 1 1 upstream of the scoring and adhesive applicator rolls.

Referring now to FIG. 4, the diaper is seen in its partially unfolded condition and designated D. It is in this configuration that the diaper is ready to receive the body of an infant. The foreshortened lines of compression 13-16 cooperate with the interrupted portion 12c of the line 12 to define the relatively rounded, unstressed crotch-forming portion the absence of intentional creasing, but the presence of slight rounding being illustrated in FIG. 4 by means of a series of dotdash lines in the central portion which is encircled by a dashed line designated P.

Still referring to FIG. 4, the points of adhesive (as at 22 and 23) develope an imaginary line 54 which ultimately becomes a rounded leg outfold when the diaper is applied to the body of an infant. It will be appreciated that the term outfold is used in contrast to an infold" which is developed, for example, along the line 14, viz., where the confronting, abutting faces of the fold are the inner liquid permeable sheet. However, up to the time of applying the diaper to the infant, no outfold exists along the imaginary line 54, but instead, a relatively flat or thin wing, as at W (see FIG. 2), exists. Thus, the provision of the various lines of compression, along with the adhesive spots, not only develops a thin, advantageously packageable diaper, but one which results in the provision of a body-conforming leg outfold. The advantageous thinness or compactness can also be appreciated from FIG. 3 which represents the diaper D in a partiallly unfolded condition, and wherein there is an infold at 15 and 16, and an outfold at 12b, and with the incipient leg outfold 54 also being shown.

The inventive diaper is capable of advantageous stacking in comparison with the heretofore provided diapers which possessed a like outfold. When the inventive diapers are stacked in aligned relation, they occupy only about two-thirds of the height of a stack of previously provided leg outfold diapers. Even when the diapers are stacked in offset condition, i.e., with only the waist portion overlapping, there is still a saving of about one-quarter of the stack height.

I claim:

1. A generally rectangular disposable diaper comprising an outer impermeable sheet, a layer of liquid absorbing material and an inner liquid permeable sheet all united perimetrically,

said diaper having a central transversely extending of the crotch-forming portion of the diaper and short of the inner end of its associated segment and cooperating with said associated segment to provide a relatively rounded, unstressed crotchforming portion, said diaper prior to installation on an infant being folded along said interrupted line and having an outfold along each line segment and an infold in said crotch-forming portion, and further 'having an infold alongeach convergent line whereby said diaper is relatively thin for packaging, and means adhering said inner sheet together adjacent each longitudinal edge but spaced inwardly therefrom on opposite sides of each of said convergent lines of compression to provide a rounded leg outfold in said diaper when applied to the body of an infant, said leg outfold extending generally along an imaginary line connecting a pair of adhering means adjacent one longitudinal edge. 

1. A generally rectangular disposable diaper comprising an outer impermeable sheet, a layer of liquid absorbing material and an inner liquid permeable sheet all united perimetrically, said diaper having a central transversely extending interrupted line of compression whereby the diaper is adapted to be folded on itself to provide a crotch-forming portion in the middle of said interrupted line of compression, said line having a segment extending in from each longitudinal edge with each segment terminating short of the crotch-forming portion of the diaper, a pair of inwardly convergent foreshortened lines of compression associated with each of said segments and disposed at about 45* relative thereto, each of said convergent lines of compression extending in from each longitudinal edge but terminating short of the crotch-forming portion of the diaper and short of the inner end of its associated segment and cooperating with said associated segment to provide a relatively rounded, unstressed crotch-forming portion, said diaper prior to installation on an infant being folded along said interrupted line and having an outfold along each line segment and an infold in said crotch-forming portion, and further having an infold along each convergent line whereby said diaper is relatively thin for packaging, and means adhering said inner sheet together adjacent each longitudinal edge but spaced inwardly therefrom on opposite sides of each of said convergent lines of compression to provide a rounded leg outfold in said diaper when applied to the body of an infant, said leg outfold extending generally along an imaginary line connecting a pair of adhering means adjacent one longitudinal edge. 